Im with lindyline on this one. I dont read dental xrays but am certified to read skeletal ones. Cracks often do not show immediately. The swelling or bruising in the area will cause the two pieces to be pushed together and you cant see the crack especially one that is oblique through the bone. Once the swelling recedes the crack opens up. This is such a frequent phenomenon that years ago, in private doctor's offices, the standard was to xray the area twice, once immediately and once in 24-48 hours after the swelling receded, before you stated there was absolutely no fracture. Now we have CT and MRI that are readily available.
If you were my patient, I would see you again immediately.